Chiller capacity is inadequate

Objective/Method/Outcome

Objective: Determines if the chiller is unable to bring the water temperature down to the temperature setpoint during operational hours.

Method: Compares the chilled water temperature to the maximum chilled water to determine if the chilled water temperature is over acceptable during operational hours for over the weekly acceptable threshold.

Outcome: Triggers an insight.

Applicable System

CWS

Description

Monitors chilled water supply temperature while chiller is active to determine if chiller is unable to bring water down to suitable temperature. This rule is part of the CopperTree Standard rule-set.

Diagnosis

  1. Review temperature sensor calibration.
  2. Chiller capacity may be inadequate.

Message

Chiller capacity may be inadequate, as CHW supply temperature is above threshold.

Rule Template

Insight Type: Fault Detection

Trigger Type: Active High

Default Priority

Medium

Logic

Logic flow to determine chiller capacity is inadequate

Inputs

Input Unit Tag Description
Chiller Status Chiller Status, Chiller Command The recorded status of the chiller
Threshold – Weekly Hours of Faulty Operation The minimum amount of faulty operation to trigger insight
Chilled Water Supply Temperature °C/ °F Chilled Water Supply Temperature The recorded chilled water temperature
CHW Maximum Supply Temperature °C/ °F The preset upper limit of the chilled water supply temperature

Notes

Default Values:

  • CHW Supply Temperature Maximum: 50°F or 10°C
  • Threshold – Hours of Faulty Operation: 4